@@ -14,10 +14,12 @@
  * file.
  */
 
 #import "OFSet.h"
 
+OF_ASSUME_NONNULL_BEGIN
+
 /*! @file */
 
 #ifdef OF_HAVE_BLOCKS
 /*!
  * @brief A block for enumerating an OFCountedSet.
@@ -63,5 +65,7 @@
 #endif
 @end
 #if !defined(OF_HAVE_GENERICS) && !defined(DOXYGEN)
 # undef ObjectType
 #endif
+
+OF_ASSUME_NONNULL_END